Telephone system.



PATENTED SEPT. 11, 1906.

I No. 830,981.

A. H. DYSON. TELEPHONE SYSTEM. APPLICATION FILED APR. 17. 1905.

4 SHEETS-SHEET 1.

INVENTOR PATENTED SEPT. 11 1906.

No. 830,981. A. H. DYSON.

TELEPHONE SYSTEM.

APPLICATION rum) APE.17, 1905.

4 sums-sum 2.

[/92 Like-f5 Iwvamoa PATENTED SEPT. 11', 1906.

A.'H. DYSON. TELEPHONE SYSTEM.

APPLICATION FILED A'PB. 17. 1905.

4 SHEETS-SHEET 3.

INVENT0R1- WITNESSES?- No. 830.981. PATENTED SEPT.11, 1906. A. H. DYSON.

TELEPHONE SYSTEM.

urnouxox run an. 11. 1905.

.4 sun's-sum g UNITED STATES PATENT OFFICE.

ALFRED H. DYSON, OF CHICAGO, ILLINOIS. ASSIGNOR TO MILO G. :KELLOGG, OF CHICAGO, ILLINOIS.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Sept. 11, 1906.

Application filed April 1'7. 1905. I Serial No. 256.063.

To rtZZ ZUh/QTIL it may concern.-

Be it known that I, ALFRED H. DYSON, a citizen of the United States, and aresident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Im rovements in Telephone 7 Systems, of which the following is a specification.

My invention relates totelephone systems, and more specificallyto providing apparatus for giving a special and auxiliary service in connection with such systems. 'The special service referred to consists in supplying means by which, from a substation a plurality of teiephone-lines may be simultaneously connected to the line of the said substation, and means whereby the bells of all such 'lines 'm-ay be simultaneously rung) news by telephone simultaneously to a num- 'ber of offices from a central news-bureau.

Another application would be the-employment of my invention for the purpose of enabling the subscribers to an exchange to give information in case of firesimultaneously to the different engine-houses of a city fire department.

Figure 1, consisting of Sheets 1, 2,'and 3, illustrates diagrammatically an application of my invention to an automatic telephoneexchange system. In the said Fig. 1 I have shown in addition to the apparatus specifically belonging to my invention apparatus adapted to be used in the ordinary course of exchange service; but I do not claim this latter by itself as my invention. In Fig. 2 I show a selective switch that may be employed in connection with my invention. Fig. 3 is a top view of the vertical magnet of said switch and its associated parts. Fig. 4 is a side view of the vertical magnet. Fig. 5 is a view in perspective of the side switchpawl and its parts. Fig. 6 is a top view of urpose of distributing the rotary magnet and its parts. Fig. 7

shows a mechanism ca able of being em- I ployed in connection wit circuit D of Fig. 1. Fig. 8 shows an alternate mechanism for circuit D- of Fig. 1.

Referring to Fig. 1, I show at A, in dia-.6o

grammatic form, substation apparatus, including a pair of keys P and S, adapted to be used at will by the subscriber or attendant to ground at the substation limbs p and s of the telephone-line, respectively. At H,

I have illustrated diagrammatically an automatic switch, ordinarily called a first selector-switch, which, as shown, comprises the passive or immovable contact pieces or terminals 86, 87, and 88and the active or mov- 7o able contact-pieces or wipers 18, 19, and\20, together'with a suitable organization of circuits and electromagnets to render said wipers controllable by means of keys I and S.

At E, I have shown an automatic switch, or-

dinarily called a second selector-switch,

comprising passive contact-pieces 27, 28,

'and'29 and wipers 32, 33, and 34, together with an arrangement of electromagnets and wipers. At F, I have shown an automatic switch, ordinarily called a connectorswitch, provided with passive contactpieces 35,- 36, and 37 and wipers 44, 45, and

circuits for controlling the movements of said 46, with a suitable organization of electro- 8 magnets and circuits for controlling the movements of the said wipers. At C, I hai e shown a second substation similar to that shown at A, and at G an automatic switch connected with the said substation by the 0 two limbs of its telephone-line, the said switch comprising passive contact pieces 47, 48, and 49 and wipers 89, 90, and 91, with circuits and electromagnets for controlling movements'of the said wipers.

The above-described apparatus includes that necessary for establishing a connection between subscribers A and C in connection with the telephone system in association with which I have elected to describe my .in 1 op vention. The following is a brief description of the method of operation of the said systern: Assumingthat the number of subscriber C Is 2345 and subscriber A desires connection with subscriber -C, subscriber A 105 first sends, by means of key P, two impulses of current from ground at the substation through relay 7 of first selector-switch H.

This causes a movement of wipers 18, 19, and 20 such as to'bring them into a position ready to engage miiltipled terminals of second selector-switches adapted to be used in establishing connection with a limited group of subscribers lines, which is assumed to be a grou of one thousand lines,- including lines of su scribers to whom are'assign d numbers from 2000*- to 2999,? inclusive. Adapted ,to be successively engaged by wipers 18, 19,

and 20 are-multipled terminals of a plurality of such switches. Subscriber A now sends, by means of key S, one impulse of current from ground over limb s through relay 11 of switch H, which causes wipers 18, 19, and 20 to move into engagement with terminals of the first switch of the group above mentioned. In case the first switch is busy its terminal, corresponding to terminal 2-7 of switch E, will be grounded and wipers 18, 19, and 20 will be started upon a series of independent prof gressive movements over terminals of successive switches of the group until they rest inengagement with terminals of an idle -minals of a switch, at which time the aforesaid move- .ment ceases, owing to an absence of ground ,erate to place 'wipers 32, 33, and. 34 of switch E in a position ready to engage multipled. terlurality of connector-switches, each adapted? nection with a one-hundred-line group of subscribers lines, to whom are assigned numberfl'rom 2300 to 2399, inclusive. Subscriber A now 'sends,by means of key S, one impulse of current over limb s of theline, which in this case asses through relay 31,

which operates to p ace wipers 32, 33, and 34 in engagement with terminals of the first connector-switch of the group above mentioned. In case such switch is busy an independent movement of wipers 32, 33, and 34 is caused in a manner similar to that before des cribed, the movement of the wipers being arrestedwhen they engage terminals of an idle, connector-switch, assumed to occur when they engage, respectively, terminals 35,36, and 37 of connector-switch F. Su'bscriber A now sends, by means of key P, four impulses of current from ground over limb p of the telephone-line, in this case passing through relay 38 of connector -'switch F, which impulses operate to place wipers 44, 45, and 46 in a position such that they are ready to be caused to move over terminals of to be used in establishing cona group of subscribers lines, to whom are as signed numbers from 2341 to 2350, in-

clusive. Subscriber A now sends, bymeans of key S, one impulse of current over limb s of the telephone-line, which in this case passes through relay' 39, operating to place wi ers 44, 45, and 46 under control of a secon set of impulses to be sent through relay 38.

Subscriber A now sends, by means of key P,

five impulses of current over limb p of the line, passing through relay 38, which causes wipers 44, 45, and 46 to move over terminals of successive subscribers lines until they reach terminals of the line of subscriber 2345 or subscriber C. In case this line is already in use contact-piece 47 will be grounded, and when subscriber A, by means of key S, sends one impulse of current over limb 8 through relay 39, as he now proceeds'to do, wipers 44,

45, and 46 disengage contact-pieces 47, 48,

and 49, respectively, and return to normal. Subscriber A now sends, by means'of key P, an impulse of current over limb p, which passes through relay 38 and in this case operates to cut busy back machine 43 into circuit with the line of subscriber A and causes him to receive the usual busy-signal by means of his receiver. In case the line of subscriber C is not busy wipers 44, 45, and 46 rest in engagement with contact-pieces 47, 48, and 49, and the impulse of current last described as being sent by subscriber A, by

means of key P, causes the energization of relay 42, operating to cut ringing-generator 92 into circuit with the line of the called subscriber, causing his bell to. ring and notifying himthat his attention is desired. When subscriber A releases key P, relay'42 is de energized and the talking-circuit of the lines established. When the subscribers have finished their conversation, they replace their receivers and respectively send, b means of keys P and S, simultaneous impu ses of cur rent from ground-over their respective telephone-lines. In case the called subscriber C does-this first-connector-switch F returns to normal, and when subscriber A does so switches H and E return to normal. In case subscriber A sends the aforementioned simul-v taneous impulses of current. before subscriber C switches F, E, and H all return to normal.

Generally speaking, the automatic telephone system illustrated may be said to operate as follows: The subscriber desiring to make a call operates a first selectorconnector-switch to pick out from the onehundred-line sired.

The mechanism of a switch, such as diagroup the individual line degrammaticallly shown at H, E, F, and G,

may conveniently be constructed to comprise a shaft upon Wl'llGl'l the Wipers are rigidly mounted, the energizing impulses sent, by the subscriber over limb \p in making a,"

call causing successive vertical movements of the shaft to bring the'wipers into uxtapo- 'sition'with different horizontal curved rows. The.

independent progressive movements of se-- or levels of terminal contact-pieces.

lector-switches, referred to in the foregoing description as started. by impulses of current sent over limb s of the telephone-line, may be effected by imparting a rotary motion to the shaft, which may be axially dis osedwith respect to the varioushorizonta rows of contacts. In the case of connector-switch F this rotary motion is of course not. of amindependent character, but is controlled by a series of impulses-sent over limb p of the line. Having described, in a general way, the operation -of the telephone system in connection with which I show' the-special-service system, I will now describe in detail the circu-it arrangement and method of operation of the latter. 7

In Fig. 1, B and C may be regarded as substations located in. two different enginehouses of a fire-department. The substation illustrated at C is shown-connected by the two limbs of its telephone-line with contactpieces 18 and 49 of a first selector-switch G at the central oflice, the arrangement being such that calls may be made and received by the substation in theordmary course of business in a manner. similar to that described station C to the switching mechanism of relay 7 2, terminating t-hereat in anvils 77, 75, and 78, respectively. Similar conductors are provided leading from contact-pieces 92', 93, and 94 of the switch of substation B to the switching mechanism of relay 72 terminating thereat in anvils 77, and 78. Referring now to D, I there show a switching device including passive contact-pieces98, 21, and 22 and active terminals 66, 68, and 70, together with a suitable organization of circuits for operating the special-service system of my invention. Contact -,pieces 98, 21, and 22 are adapted to be engaged by wipers 18, 19, and 20 under control of the A. The said contact-pieces 98, 21, and 22 are preferably located'upon a level individual to themselves and. are preferably the only contact-pieces upon that level and soplaced that the first rotary movement of the shaft will bring the wipers of the selector switch into engagement with them. Assuming that the said contact-pieces 98, 21, and 22 are placed upon the ninth level, so that nine vertical 'stepby-step 'movements are to be imparted to shaft 80 of first selectorswitch H to bring wipers 18, 19, and 20 into a position such that upon a rotary movement of the shaft they will engage said contactpieces, and that subscriber A desires to employ the special-service arrangement, the operation of the system is as follows: Suhscriber A depresses and releases key times, thus establishin nine temporary ground connections to lim p of the line at the 'substation and sending nine im ulses of cur-.

rent over the said limb by the in lowing path: from ground, over limb p, through arm 07',

through the winding of relay 7 to battery 17,

causing'nine energizations and denergizations of the said relay. The resulting attractions and releases of the relays armature cause nine. impulses of current to flow over. the following path: from ground, through contact between springs 9 and 8,

- through contact 13 15, throughthe winding of magnet 16 to battery 17, resulting in nine energizations and denergizations of -magnet 16. Magnet 16,; by mechanical connections, (not shown,) thereby is caused to elict ninevertical step-by-step movements of shaft 80, bringing wipers 18, 19, and 20 to positions horizontal Wliil'l'COl'liSlGiJ-PlGCQS 98, 21, and 22. Subscriber A now depresses and releases key S a single' time, causing one impulse of current to flow from ground at the substation, over limb s of the line, through arm (1 through the winding-of relay 11 to. battery 17, energizing and denergizing the said relay and causing the attraction and release'of its armature. rent is thereby caused to flow over the following path: from ground, through contact between springs 9 and. 10, through the winding.

of relay 12 to battery 17 energizing and deenergizing the said magnet. Bymechanical means (not shown) the consequent attraction and release of the armature of relay 12 effects the followingcircuit changes: arms a, a, a and a are moved into engagementwith contact-points b, b, and 6 respectively. The engagement of arm a with contact -point 6 establishes a path for the flow of current from ground, through contact a I), through magnet 23 to battery 26,'causing the energization of magnet 23,

nine

An impulse of" cur- TOE which thereupon attracts its armature, break-' ing its own energizing-circuit. The energization' described of magnet 23 by mesubstation switching apparatus shown at chanical means (not shown) effects a rotary I movement of shaft 80, so that wipers 18, 19,

into engagement 'key P and releases it, which operates to establish a talking-circuit from his line through to substations B and O in'the following manner: The depression of key P establishes a path for'the flow of current from. r 5 g roundat the substation over limb p of the line, through contact (1 through contact 19 21, through relay 50 to battery 57, ener gizing the said relay. This energization attracts the relays armature andestablishes a path for the flow of current as follows: from ground at switch D, through contact between springs 55 and 54, through contact between springs 52 and 51, a portion of the current then flowing through relay 81 to battery 57 causing the energization of the said relay. The denergization of said relay upon the release of key P ,by mechanical means (not shown) moves active terminals 66, 68, and

70 into engagement with contact-points 67,

69, and 71, respectively. A portion of the described flow of current also passed through the winding of relay 64 tobattery 57, energizing the said relay and causing the attraction of its armatures. The generator-circuit was at that time open at contacts 68 and 70.

The enga'gementof active terminal 66 with.

contactpoint 67 established a path for the flow ofcurrent from ground, through contact 66 67, over conductor 83, the said current passing in parallel through the windings of relays 72 and 7 2 to battery 73, causing the energizations of the said relays. It is apparent that these relays will continueenergized until terminal 66 disengages contact-point 67 as hereinafter described. The energization of relays 72 and 7 2 caused the attraction of their armatures, the resulting closing of contacts 76 77 of relay 72 and 76 77 -of relay 72 connecting contact-pieces 47 and 92 to ground and rendering the lines of stations C and B busy with respect to incoming calls in the regular course of business. The energization of relays 72 and 7 2 also resulted in bridging the lines of substations 'C and B across conductors 84 and 85. Subscriber A again depresses key P, resulting in a flow of current through relay 64, as before described, this time cutting ringing generator into circuit with conductors 84 and 85, ringingcurrent therefrom passing through the bells of the two substations C and B. When subscriber A releases key P, circuit is broken through relay- 64, denergizing the said relay. Its arm'atures return to their normal positions, (shown in the illustrations,) estabator 65 out of circuit with conductors 84 and 85. When the call is responded to at substations'C and B, subscriber A is able to simultaneously give such information as he desires to the persons who answer the call at substations C and B,'the conversational circuit being traced from substation A, over limb p of the line, through contact a? 0 contact 19 21, 'through condenser m, through contact 68 69, over conductor 84, over the telephone-lines of substations C and B in parallel, returning over conductor 85, through contact '71 7 0 ,through condenser m" through contact 22 20, through contact 0 a over limb s of the line 'zfid through substation A. Having given the 'dfired information, sublishing the talking-circuit and cutting ge'ne'rscriber A simultaneously depresses keys P and S and releases them, thus grounding simultaneously limbs p and s of'his telephoneline. Current is thereby caused to flow from ground, over limb p of the line, through contact 19 21, through relay 50 to battery 57, and from ground at the substation over limb s of the line, through contact 20 22, through relay 56 to battery 57. Relays 50 and 56 are thereby energized, establishing a path for the flow of current as follows: from ground at switch '1), through contact between springs 55 and 53, through the winding of magnet 58 to battery 57. This flow of cur- ,rent energizes magnet 58, attracting its armature 95, causing a flow of current from battery 57, through resistance 97, contact 98 18, relay 25, contact a c to ground. Relay 25 attracts itsarmature, causing a currentflow'from ground, through magnet 24 to battery 26, energizing magnet 24. When subscriber A releases the keys at his substation,

circuit is broken by the resulting denergization of relay 56 through magnet 58, and its deenergization by mechanical means (not IQS.

shown) causes active terminals 66, 68, and a 7 O to disengage, respectively, contact-points 67, 69, and 71, returning to their normal positions, as. illustrated. The disengagement of terminal 66 from contact-point 67 opens circuit through relays 72 and' 72 denergizing them, allowing the return of their armatures to normal, thus breaking the bridges of the'line of subscribers C and B to conduc-i tors 84 and 85 and also removing ground from contact-points 47"and '92, associated with the lines of substations C and B, wherethe release described, it is essentialin regular tact 78 79.

service operations and would in practice be done, and I have therefore so described the operation. 1

The special-service "circuit also rovides means whereby after subscriber A as conveyed the desired information the release' of the line of the called substations may be secured by switching operations formed at one of the called substations. Assuming thatthis is to be done from substation C, the operation is as follows: By means of ke'ys P and S the two limbs of the telephone-line of substa-. tion C are simultaneously grounded. This places a ground on conductor'84 through contact '75 74 and on conductor 85 through con- Current s thereby caused to flow from ground at substation C. over conductor 84, through contact 69 68, through relay 59 to battery 57, and over conductor 85, through contact 71 70, through relay 60 tobattery 57. These flows of current cause a simultaneous energization of relays 59 and 60, attracting th oir armaturci; and causing a flow of current over the following path: from ground at switch l), through springs 63 62 61, through the winding of magnet F and to battcry 57. When the keys at subs tation C are released, relays 5953M 6 O'are deenergized and the return of their armatures to normal opens circuit through magnet 58, dei nergizing the said magnet and causing the return-by mechanical means '(not' shown) of active terminals 66, 6S,and 70 to their normal positions and also of wipers 18, 19, and 20. Should contact-piece 98 be omitted from the switch -D, means would still be provided,-'operable either by the calling subscriber or by any one of the called stations, for releasing the said called stations and returning them to their normal or idle-circuitconditions but it would be impossible to automatically disconnect switch H from switch D, as described above, and under these conditions this would have to be done by an attendant at the central ofi ice. I consider this latter in some respects a desirable method of operation in connection with the fire-alarm service I have described, as in case an alarm should be given of an improper or mischievous nature the latter method of operation would enable the source of such alarm to be traced, while knowledge that means are provided for this purpose will act as a deterrent to persons who might other wise give such alarms.

The terminals 98, 21, and 22 of the specialservice circuit may be multiplied throughout the switches of the exchange in such a manner as to enable each subscriber to obtain connection with and operate the specialserv ice circuit, substations such as C and B,

7 whose lines are thrown together upon the operation of the special-service circuit. being able to do this also.

The multiplying of the terminals of the special-service switch may be done in a valines-together in the manner described. My

invention is susceptible to widely-varying arrangements and 1s not'to be limited in this respect. r

It is to be understood that the terminals of the special-service switch need not be associated with wipers of first selector-switches, but may, if desired, be associated with wipers of second selector-switches or connectorswitches. The aforementioned and other modifications may be readilymade without departing from the substance of, my invent-i on, which is of general application, and I desire not to be limited to the particular arrangements shown. l

While I have shown'aplurality of batteries in Fig.1, it is to be understood that they may be one and the same battery. 1'

In practice a substation calling device not requiring by the subscriber the amount of care involved by the'use of the simple keys P and S would be provided.

Having described the circuit structure of my invention, I will now refer to the mechanical drawings, illustrative of certain mechanism that may conveniently be used in connection with my invention. Any suitable form of mechanical switch may be employed in. connection with the circuits shown at H, E, F, and G, that shown in Fi 2 being a diagrammatic representation 0 a switch in extensive commercial use in the United States. For convenience of reference I have supphed characters to F1 2 corresponding to those of circuit H, alt ough the switch shown in said Fig. 2 is eneric to and equally adapted to be operate .in connection with circuits E and G and with the omission of ar 23" for circuit F. In said, Fig. 2 shaft as fastened to it wipers 18, 19, and 20, adapted to be raised and rotated with the shaft, which is j ourn aled to thesupports of contact-banks L and 1. For securing these movements of the 7 too shaft the vertical magnet 16, with its armature-actuated pawl 16, is provided, the pawl being arranged to engage the horizontal teeth of the ratchet shown fastened to the shaft 89. YVith the first energization of ma net 16 pawl 16 raises the shaft a step and ugs 16-- and 16 of the armature of magnet 16release, respectively, double dog d d, which engages with its upper portion a horizontal tooth of the shaft-ratchet to prevent back movement, and arm 12 from its interlocking relation with the pin on the armature of the releasemagnet 24, which renders side-switch pawl 12 capable of movement, as hereinafter in- ""35 isi'ndicated the manner in which each move- 1 to pawl I2 ,-is thereby caused to move off its normal contact to engage contact I). In Fig.

merit of pawl 12 effects a plurality of simultaneous circuit changes. Rotary movementsof shaft 80, causing the engagement of wipers 18, 19, and 20 with the contacts of selected levels, of their banks, is accomplished by thrusts of pawl 23*, fastened to the armature of rotary magnet 23. Each time magnet 23 is energized a thrust of the pawl is caused, which engages the teeth of the vertically-disposed ratchet of the shaft successively, the lower portion of double dog d d engaging successive teeth of the ratchet and preventing back movement. The shaft 80 is thus ro tated, each rotary step causing wipers 18, 19, and 20 to engage successive contact sets of selected levels. The arm 2. a is provided for the selector-switches only (being omitted in the connector-switches) and is adapted to thrust the armature of side-switch magnet 12 to the right when magnet 23 is energized, allowing the said armature to be retracted when magnet 23 is denergized. T he described movement of the armature of sideswitch magnet 12 causes pawl 12 to advance t9 engage tooth 12 thereby placing arms a a a, &c., in engagement with their third contacts c 0 &c. This is the method of operat tion hereinbefore referredto as causing arms a, a, a and a to engage contact-points c, 0, c and c at the time'when wipers 18, 19, and engaged contacts 98, 21, and 22, the said contacts being assumed to be the first and only connected contacts of the ninth levels,

5 In regularservice operations the function of arm 23 is to cause the side-switch arms to engage their third contacts when the first trunk of the'selccted group is idle. If this trunk is busy, 7 side-switch magnet 12 becomes energized as arm 23 completes its stroke and holds the armature attracted, thus preventing movement of the side-switch pawl 12 until an, idle trunk is reached by the wipers, when magnet 12 becomes deengerized and pawl 1-2 moves to engage tooth 12. To restore the switch to normal, releasemagnet 24 is energized and deenergi zed, whereby its armature is attracted and then retracted. 'W hen attracted, it moves pivoted arm 24 to the left to engage with itshook the pin upon double detent d (1, while the pin upon nnature engages the offset of arm 12". When ,he armature of magnet 24 18 now retracted,

it moves arm 12 .to the right, resetting pawl 1 in enga ement with tooth 12 to restore arms a 0,. a, &c.,'wh1le arm 24. simultaneoiisly withdraws the double detent d d from engagement with the shaft-ratchets, leaving the shaft free to be rotated, bypspring 80 (against whose torsion itwasiturned) until wipers 18,"1,9,and 20 pass to the left of banks L and 1, when the shaft is free to descend to normal under theinfluence of gravity, assisted by sprin 80 In Flg. 7 show an adaptation of the sideswitchoperatingand restoring mechanism of Fig. 2 arranged for employment in connection with circuit D. Like parts of circuit D and Fig. 7 have corresponding characters. Referring to Fig. 7, when, as hereinbefore described, magnet 81 is energized its attracted armature moves arm 81 downwardly, whose pivoted arm 81 withdraws arm 58 from engagement with pin 81 on side switch pawl 81*, thus terminating the normal locked condition of said pawl, so that with the ensuing deinergization of magnet 81 and the consequent rctraction of its armature the said pawl moves to engage tooth 81, carrying switch-arms 66, 68, and 70, fastened to the pawl, into engagement with their respective contacts 67, 69, and 71. When now magnet 58 attracts its armature, arm 58 is moved to the left, so that the offset at its extremity engages pin 81" upon pawl 81-. VVhe'n magnet 58'. is thereupon deonergized, its retracted armature moves arm 58 to the right,'which, continuing' in engagement witli lpin 81", moves p: WI 81 to again engage toot lr8r1f5, the pawl in its return movement carrying switch-arms 66, '68, and. out of engagement with contacts 67, 69, and 71 and to their normal positions, as shown in Fig. 7. Another arrangement of mechanism adapted for use in connection with circuit D is shown in Fig. 8. Here magnet 81 is provided with a single-hooked spring 81 ,-fastened to its armature. When 81 is energized, the attraction of its armature draws spring 81 down to release pawl 81, which is thereupon moved, as usual, by its associated spiral spring, causing switch-arm 66 to engage contact 67. Arm 58, pivoted to pawl 81*, having an orifice fitting over pin 58' of the armature of magnet 58, limits the movement of the pawl When magnet 58 isenergized, its attracted armature, acting by means of pin 58 upon arm 58, causes pawl 81 to again slip into a position where it is held by toothed spring 81 arm 66 being simultaneously returned to normal.

In the employment of the structure of Fig.

8 the depression of key P after switch H has selected switch D moves arms 66, 68, and 70 to engagetheir alternate contacts,-.and if key P is kept depressed ringing-current is imme the ar diate'ly thereafter projected over the specialservice lines.

Having shown a preferred embodiment of my invention, I shall claim the same broadly, it being my intention not to limit myself in the broad claims to the particular embodi- -ment herein particularly set forth, includingthe combination of my invention with an automatic telephone system.

I claim- 1. In an electrical exchange system, a plurality of lines connecting substations with the exchange, apparatus for each line at the exchange for regular service, a line connecting a calling-substation with the exchange, a special-service circuit associated with said plurality of lines at the exchange means for operating said circuit from the calling-substation to switch said plurality of lines intoa con'nnon electrical circuit with said line and means for electrically transmitting intelli. gence over said common circuit when established.

2, In an electrical exchange system, a plu-' rality of telephone-lines connecting substa' tions with the exchange and provided with line-circuits for regular exchange service there'at, a telephonedine connecting a callingsubstation with the exchange, and a specialservice circuit at" the. exchange associated with said plurality of lines, adapted to be operated from said calling-substation to switch said plurality of lines into a common conversational circuit including the line of the calling subscriber.- r

4. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange and provided with line-circuits for regular exchange service thereat, a telephone-line connecting a calling substation with the exchange, a special-service circuit at the exchange associated with said plurality of lines, adapted to be operated from said calling'substationto switch said plurality of lines intoga common conversational circuit including the line of the calling subscriber, means controlled from the calllng-substat on forrmgmg the SllbStBtlOllS' of said plurality of lines when so switched and apparatus operable from any substation in-' cluded in said conversational circuit to destroy such circuit.

5. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, a line-circuit for each line at the exchange, a special-service circuit at the exchange, a relay for eachof said lines associated with said special-service circuit, and branches extending from said lines to said relays, a telephone-line connecting a calling-substation with the exchange, and apparatus associated with said line at the exchange adapted, under substation control, to operate said relays to switch said plurality of lines into a common conversational circuit including the line of said calling-substation.

6. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, aline-circuit for each line at the exchange, a spccial-service circuit at the exchange, a relay for each of said lines associated with said special-service circuit, and branches extending from said lines to said relays, a telephone-line connecting a calling-substation with the exchange, apparatus associated with said line at the ex change adapted, under substation control, to operate said relays to switch said plurality of lines into a common conversational circuit including the line of said calling-substation, and apparatus operable from a substation included in said conversational circuit adapted to destroy such circuit.

7. In an automatic telephone-exchange system, the combina ion of a plurality of telephone-lines connecting substations with the exchange, an automatic switch for each of said lines at the exchange for ordinary service, a special-service circuit at the exchange, relays associated with said circuit, one for each of said lines, and branches extending from each line to its respective relay, a teleadapted phone-line connecting a calling-substation' with'the exchange, calling mechanism for said line at the substation, an automatic switch at the exchange adapted, in response to said calling mechanism, to connectsaid line with said special-service circuit, a central source of current, apparatus included in said circuit adapted, responsive to said calling mechanism, to switch said source in circuit with, and energize, said relays, and switching mechanism for said relays adapted, in response to their energization, to include their respective lines in a common conversational circuit with said calling'snbscribers line.

system, the combination of a plurality of telephone-lines connecting substations with the exchange,'an automatic switch for each of said lines atthe exchange for ordinar service, a special-service circuit at the exe range, relays associated with said circuit, one for 8. In an automatic telephoneexchange each of said lines, and branches extending I from each line to itsrespective relay, a telephone-line connecting a calling-substation with the exchange, calling mechanism for said line at the substation, an automatic switch at the exchange adapted, in response to said calling mechanism, to connect said line with said special-service circuit, a central'source of current, apparatus included in said circuit adapted, responsive to said calling mechanism, to switch said source in circuit with, and energize, said relays, switching mechanism for said relays adapted, in response to their energization, to include their respective lines in a common conversational circuit 'with'said calling-subscribersline, and apparatus adapted, under control of the calling-substation, to simultaneously signal the substations of said plurality of lines when so included.

9. In an automatic telephone exchange system; the combination of a plurality of telephone-lines connecting substations with the exchange, an automatic switch for each of said lines at the exchange for ordinary service, a SPGCltLl- SBIVlCG circuit at the exchange,

relays associated with said circuit, one for each of said. lines, and branches extending from each line to its respective relay, a telephone-line connecting a calliiigsiibstation with the exchange, calling mechanism for said line at the substation, an automatic switch at the exchange adapted, in response to said calling mechanism,.to connect said line with said special-service circuit, a central source-of current, apparatus included in said circuit adapted, responsive to said calling mechanism, to switch said source in circuit with, and energize, said relays, switching mechanism for said relays adapted, in response to their energization, to include their respective lines'in a common conversational circuit with said calling-subscribers' line, ap paratus adapted, under control of the callingsubstation, to simultaneously signal the substations of said plurality of lines when so included and apparatus adapted to be operated, under control of the calling-substation", to disconnect the line of said substation from said special-service circuit and return said circuit to normal.

10. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange and provided with line-circuits for regular exchange service thereat, additional telephone-lines connecting substations with the exchange and provided with line-circuits for regular exchange service thereat and "a special-service circuit at the exchangea'ssociated with said plurality of lines adapted to be operated from any substation to switch said plurality oflines into a common conversational circuit including the line of the operating-substation vided with line g service thereat, @SPBClfil-SGIVIGB circuit at the line of the operating-substation, and appara- I tus operable from any substation included in said common circuit adapted to destroy such circuit.

12. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange and provided with line-circuits for regular exchange service thereat, additionaltelephone-lines connect ing substations with the exchange and proircuits for regular exchange exf'cliai ge associ ated with said plurality of lines adapted to be operated from any substation to switch said plurality of lines into a common conversational circuit including the line of the operating-substation, mechanism controllable froii'ilthe operating-substation, adapted to ring the substations of said plurality oi lines, when so switched, and apparatus operable froii any substation included in said common circuit. adapted to destroy such circuit. e

13. In a teleph one-exchange system, a Pill? rality of telephone-lines connecting substations with the exchange, additional. telephoneelines connecting substfati ns with the exchange, a line-circuit for ead r line at the exchange for regular service, a special-service,

circuit at the exchange a, relay for each of said plurality of lines ELSS'PCXatC-(l with said special-service circuit, and branches extending from said lines to said relays, and apparatus for operating said relays, adapted to be controlled'from any substation, to switch saidplurali Y of lines into a common conversational circuit including the lineof the cbritrolling-subst ation.

14. In a tclephone-exchange system, a plu 'rality of telephone-lines connecting substations with the exchange, additional telephone-lines connecting substations with the exchange, a line-circuit for each line at the exchange for regular service, a special-service circuit at the exchange, a relay for each of said plurality of lines:associated With'js'aid ing from said lines to said relays, apparatus for operating said relays, adapted to be controlled froni any substation, to switch said plurality of lines into a common converse;-

tional circuit including the line of the conspecial-service circuit, andbranches extendtrollmg-substation, and apparatus operable from a substation included in said common circuit adapted to destroy such circuit.

15. In. a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, additional telephone-lines connecting substations with the exchange, a lino-circuit foreach line at the exchange for regular service, a special-service circuit at the exchange, a relay for each of said plurality of lines associated with said special-service circuit, and branches extending from said lines to said relays, apparatus for operating said relays, adapted to be controlled from any substation, to switch said plurality of lines into a common conversational circuit including the line of the controlling substation, mechanism, operable from the controlling-substation, adapted to ring the substations ofsaid plurality of lines when so switched, and apparatus operable from a substation included in said common circuit adapted to destroy such circuit. Y

16. In an automatic telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, a specialservice circuitat the exchange, relays associated with said circuit, one for each of said lines, and branches extending from each line to its respective relay, additional telephone? lines connecting substations with the exchange, calling mechanism for each line at its substation, automatic switches at the exchange responsive to said calling mechanism for regularservicc and for connecting any line with said special-service circuit, and apparatus included in said circuit adapted, when a line connected therewith, to switch said plurality of lines into a common conyersational circuit including the connected line.

17., In an automatic telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, a special-servicecnrcuitat thecxchange, relays associatcd witlisaid ci ciiit, one for each of saidlincs, a dii'bizanchesicxtending from each line to its respective relay, additional telephone-lines connecting substations with the exchange, calling .inechanism for each line at its substation automatic switches at the exchange responsive to said calling mechanism for regular s rvice and for connecting any line with said special-service circuit, appara tus included in said circuit adapted, when a line is" connected therewith, to switch said plurality of lines into a common conversa tional circuit including the connected line, and apparatus operable from any substation included in said common circuit adapted to destroy such circuit.

18, In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, a regular-service line-circuit for each line at the exchange ,and a special-service circuit a t the exchange adapted to be operated from, a substation of said plurality to switch said lines into a common, conversational circuit.

19. In a telephone-exchange syst-emQla plurality of telephone-lines connecting substations with the exchange, a regular-service line-circuit for each line at the exchange, a special-service circuit at the exchange adapted to be operated from a substation of said plurality to switch said lines into a common conversational circuit and apparatus operable from a substation included in such common circuit to destroy the said circuit.

20. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, apparatus at the exchange for connecting any two of said lines into an individualized conversational circuit, a special-service circuit atthe exchange, a relay for each line associated with said specialservice circuit, and branches extending from each line to its respective relay, and apparatus, adapted to be controlled from any of said substations, for operating said relays to switch said plurality of lines into a common conversational circuit.

21. In a telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, apparatus at the exchange for connecting any two of said lines into an individualized conversational circuit, a special-service circuit at the exchange, a relay for each line associated with said specialservice circuit, and branches extending from each line to its respective relay, apparatus, adapted to be controlled from any of said substations, for operating said relays to switch said plurality of lines into a common conversational circuit and mechanism adapted to-be operated from any substation ineluded in said common circuit to destroy such circuit.

22. In an automatic telephone-exchange system, a plurality of telephone-lines connecting substations with the exchange, calling mechanism for each line at its substation, automatic switches at the exchange responsive to said mechanism, adapted to connect said lines into individualized conversational circuits, a special-service circuit at the exchange, relays associated with said circuit,

one for each of said lines, and branches ex-.

tending from each line to its respective relay, and mechanism included in said switches adapted to enable any substation of said plnrality or" lines to control said circuit and operate said relays to switch said lines into a common conversational circuit.

23. In an automatic telephone-exchi'inge system, a plurality of telephone-lines connecting substations with the exchange, calling mechanism for each line at its substation,

automatic switches at the exchange responsive to said mechanism, adapted to connect said lines into individualizeiiconversational .diicuits, a special-service circuit at the exchange relays associated with said circuit, one ior each of said lines, and branches ex- 5 tending'from each lineto its respective relay,

mechanism included in said switches adapted to enable any substationof said plurahty of,

lines to control said circuit andoperate said I relays to switch said lines into a common con r6 .fversationai "circuit, and apparatus operable from any substation included in .said common circuit to destroy such circuit.

24. A telephone system including telephon'e lines extending from substations to f3 the exchange, a telephone-switchboard, a special service CII'Olllt atthe 1 exchange,

" branches extending, therefrom to certaintel-ephone-lines, means at a substation for. transmitting distinctive signals over its associated airline to operate said special-service circuit,

' andmec anism included therein adapted when said circuitis so operated to connect said lines'into a common circuit.

25. A telephone system incl I to a telephone-switchboard, means for transmitting signals over said .line s'for ordinary telephone service, branches extending from telephone-lines to switching mechanisms of 3c relays individual to them, and means for transmitting distinctive signals from a substation to cause the operation of said relays to switch said lines into a common circuit ineluding the line of said substation.

- 5' 26. A telephone-exchangesystem including telephonelines connecting substations with the exchange, terminals for said lines, apparatus for connecting therewith in the regular course ,of exchange service, caddi- 4o tional terminals for'said lines, a special-service circuit," means for transmitting distinctive signals overcalling-lines to cause the operation of saidSpeeial-srvice circuit to connect said additional terminals to the calling-line, 45 whereby a common conversational circuit is established including said telephone-lines.

, 27 In a telephone system including telephone-lines, and means at the exchange for I connecting them in pairs individualized ding substa-. -'-'z 5 tions, telephone-lines connecting said stations circuits, the combination with a lurality of 59';

crate said circuit to said line and aid certain lines into a common circuit- 29. In a tele hcne=eachangesystcm, a plus rality of telep one-lines connecting S115i= tions with the exchange, a s ecial=scr-viee iii 7 7 cuit including mechanism a apted to connect it to certain lines, a calling-substation, a se-v lective switch at the exchange, means at the substation for transmitting distinctive sig=.

nals to said switch to cause it to connect said 7 5' line with said special-service circuit and opcrate said circuit to connect said line aii1 said certain lines into a common circuit, n means operable from a substation adapted to destroyvsaid common circuit. j a 1 30, In a telephone system, telephone-lines connecting substations with the exchange,

selective switches at the exchange-for connectingjsaid lines, under substation control, in pairs for conversation,- a special-service 85 circuit at the exchange, branches extending .from said circuit to said lines, a calling-sub-' station and a calling device thereat adapted to transmitspecial signals to a selective switch to cause it to connect the line of said 90 substation with said special circuit and unite all of said lines in a common circuit.

In, witness whereof I hereunto subscribe my name this 11th da of April, A. D. 1905,

AL RED 'H. DYSOY.

Witnessesz' L. D. KELLOGG, G. E. MUELLER. 

